Yong G. Peng

Temporary Biventricular Pacing Postcardiopulmonary Bypass in Patients with Reduced Ejection Fraction

Abstract  Background and Aim: Patients with low ejection fraction (EF) undergoing myocardial revascularization frequently require ventricular pacing following cardiopulmonary bypass (CPB). While the benefits of chronic biventricular (BiV) pacing in patients with low EF are well established, there are little data on acute effects during heart surgery. This study analyzed the response of BiV versus single ventricle lead pacing on hemodynamics and left ventricular (LV) function immediately following CPB. Methods: Ten patients with decreased LV EF (mean = 35 ± 6%) underwent open‐heart surgery with CPB. Temporary pacing electrodes were placed on the right atrium, apex of the right ventricle, and lateral wall of the LV after separation from CPB. The hemodynamic effects of three atrio‐ventricular (right, left, and BiV) pacing modes were studied for four minutes each. The pacing sequence was randomly allocated with a resting period of three minutes between each mode. Hemodynamic and echocardiographic data of LV function were collected. Statistical analysis was performed with analysis of variance. Results: BiV pacing increased cardiac output by 4%, 13%, and 44% over right ventricular pacing, LV pacing, and pre‐bypass values, respectively. The fractional area of change increased significantly with BiV pacing compared to right ventricular and LV pacing (36%, 35% to 44%, p < 0.01). An increased propagation velocity of 49 cm/s compared to 38 cm/s and 40 cm/s for right ventricular and LV pacing, respectively, suggested an improvement in diastolic function. Conclusion: In patients with low EF, BiV pacing immediately after CPB significantly improves LV systolic function and cardiac output, and suggests significantly improved diastolic function.

Lung Isolation Using a Laryngeal Mask Airway and a Bronchial Blocker in a Patient With a Recent Tracheostomy

R C E UNG ISOLATION AND one-lung ventilation facilitate intrathoracic operations.1 Bronchial blockers including the rndt wire-guided endobronchial blocker (Cook Critical Care, nc, Bloomington, IN), the Univent torque control blocker Vitaid Ltd, Lewiston, NY), the Cohen Flextip Plus endobronhial blocker (Cook Critical Care, Inc), the Uniblocker (Fuji ystems Corporation, Tokyo, Japan), the Fogarty vascular emolectomy catheter (Edwards Lifesciences, Irvine, CA), and the allinckrodt double-lumen endobronchial tube (Tyco Healthare group LP, Pleasanton, CA) are the typical devices used in hese clinical situations.2-9 Conditions such as anatomic varints, difficult airway, and small stature make certain lung solation techniques relatively contraindicated secondary to the isk or danger associated with placement. There is limited ublished discussion of techniques describing lung isolation in atients with tracheostomies.9-13 Chen et al9 reported placement f a Foley catheter as the bronchial blocker in a patient with a racheostomy. Placement of double-lumen endotracheal tubes ia their tracheostomy sites was described by Coe et al.12 Later, ndros and Lennon13 showed placement of a Univent tube Fuji Systems Corporation, Tokyo, Japan) through a patient’s racheostomy site. This case report describes the combined use f a laryngeal mask airway (LMA) and a bronchial blocker to rovide lung isolation in a patient with a recent tracheostomy. n LMA can be used as an adjunct to create a conduit to place ronchial blockers in patients with difficult airways, especially atients with immature tracheostomies. This approach can be sed for patients with fresh tracheostomies who require singleung ventilation while maintaining continuous ventilation.

An unusual giant right coronary artery aneurysm resembles an intracardiac mass.

A 49-yr-old man with a history of Job’s Syndrome (Hyper IgE Syndrome), an immunologic disorder characterized by recurrent infections and connective tissue disorders, was referred to our institution for evaluation of a saccular aneurysm of the distal aortic arch and proximal descending thoracic aorta. After multiple cardiac imaging studies, including cardiac catheterization, transthoracic echocardiography, and magnetic resonance imaging, the diagnosis of an aortic root aneurysm was confirmed. In addition, a 5 4.5 cm right atrial rounded and homogenic mass was detected, occupying two-thirds of the right atrium and receiving feeding vessels from the right coronary artery (RCA). These findings suggested that this mass was most likely an angiosarcoma. In addition to the above findings, the imaging studies also showed diffuse aneurysmal coronary disease throughout the entire coronary bed. The patient was scheduled for resection of the right atrial tumor, RCA bypass, and aortic root aneurysm repair. After an uneventful anesthetic induction, a transesophageal echocardiogram (TEE) confirmed a right atrial homogenic mass with a well organized capsule attached to the anterolateral wall of the atrium

Effects of Combined Levosimendan and Vasopressin on Pulmonary Function in Porcine Septic Shock

This study aims to determine whether levosimendan combined with arginine vasopressin infusion supplemented with norepinephrine can improve hemodynamics and pulmonary dysfunction. The study was tested in a fecal peritonitis-induced septic shock model, we observed that levosimendan combined with arginine vasopressin supplemented with norepinephrine therapy resulted in lower mean pulmonary artery pressure, lactate concentrations, arterial total nitrate/nitrite, and high-mobility group box 1 levels; decreased lung wet/dry ratio, and pulmonary levels of interleukin-6, total histological scores, and improved pulmonary gas exchange when compared with norepinephrine group. Levosimendan combined with arginine vasopressin supplemented with norepinephrine infusion shows potential benefit in sepsis-induced acute lung injury by decreasing mean pulmonary artery pressure and attenuating inflammatory responses in the lung compared to norepinephrine infusion alone.

Neurobehavioural abnormalities induced by repeated exposure of neonatal rats to sevoflurane can be aggravated by social isolation and enrichment deprivation initiated after exposure to the anaesthetic

BACKGROUND We tested the hypothesis that developmental effects of repeated neonatal exposure to sevoflurane in rats are exacerbated by stressful experiences received later in life. METHODS Sprague-Dawley male rats received sequential exposures to 3% sevoflurane for two h on postnatal days (P) six, seven, and eight. After weaning at P21, rats were housed either in pairs in an enriched environment (EE) or singly in an enrichment-deprived environment (an adverse environment, AE). The hippocampal concentrations of brain-derived neurotrophic factor (BDNF), and synaptic markers were assessed at P8 and P53. The dentate gyrus neural progenitor proliferation was evaluated at P11 and P53 after administration of bromodeoyuridine (BrdU) at P8 to P10 and at P22 to P27, respectively. Neurobehavioural evaluations were performed at P49 to P53. RESULTS Repeated sevoflurane exposure acutely reduced concentrations of BDNF, synaptic markers and neural progenitor proliferation. The sevoflurane group housed in the AE conditions (sevoflurane+AE) had decreased concentrations of BDNF and synaptic markers, and survival of new granule cells and impaired cognitive function compared with the control+AE, control+EE, and sevoflurane+EE groups. The neurobehavioural parameters in the sevoflurane+EE and control+EE groups were similar. CONCLUSIONS Neurocognitive abnormalities induced by repeated neonatal exposure to sevoflurane can be aggravated by stressful conditions such as social isolation and enrichment deprivation.

Effects of electroacupuncture of different intensities on energy metabolism of mitochondria of brain cells in rats with cerebral ischemia-reperfusion injury

ObjectiveTo observe the effects of electroacupuncture (EA) of different intensities on lactate dehydrogernase (LDH), succinate dehydrogenase (SDH) and ATPase in brain tissue of rats with cerebral ischemia-reperfusion injury (CI/R).MethodsForty male SD rats were uniformly randomized into sham operation group (group A), CI/R group (group B), CI/R+5 mA EA (group C), CI/R+3 mA EA (group D) and CI/R+1 mA EA (group E) groups with eight rats in each group. Transient general brain ischemia was induced by four-vessel occlusion and reperfusion. The rats in group C, group D and group E were punctured and stimulated at Baihui (GV20), Mingmen (GV4) and Zusanli (ST36) with the same intermittent and rarefaction-dense wave (30 to 50 Hz) and different electric current intensities: 5 mA, 3 mA and 1 mA for 20 min after CI/R. Then the activities of Na+-K+-ATPase, SDH and LDH in mitochondria of brain tissue were measured by spectrophotometry. The ischemic cerebral cortex tissue was taken for observing the ultrastructure changes of impaired nerve cells.ResultsCompared with group A, the activities of LDH, SDH and Na+-K+-ATPase were lowerer in the group B (P<0.05 or P<0.01). However, the activities of LDH, SDH and Na+-K+-ATPase were higher in the group D than those in the group B (P<0.05 orP<0.01). In group A, the anatomical structure of the cerebral cortex cells was basically normal; in group B, the neuronal cellular structures were severely damaged, the neuronal mitochondria got swelling, the mitochondrial cristae were broken, the medullated nerve fifibers were not integrated. In group C, group D and group E, the ultrastructure of impaired neuron were improved. Group D was the best among three groups above.ConclusionEA of 3 mA intensity could strengthen aerobic metabolism by elevating the activities of SDH and LDH, meanwhile maintaining the ionic equilibrium in the exterior and interior brain cell and relieving the cellular edema by reinforcing the activities of Na+-K+-ATPase.

Emergent limited perioperative transesophageal echocardiography: should new guidelines exist for limited echocardiography training for anesthesiologists?

Bedside limited echocardiography, or focused cardiac ultrasound, continues to gain popularity in many emergency rooms, intensive care units, and operating rooms as a rapid method of assessing unstable patients. Effective monitoring of cardiovascular function in conditions like cardiac arrest or near-arrest is the crucial step to guide successful resuscitative efforts. Transesophageal echocardiography (TEE) has emerged as one of the preferred cardiac diagnostic and monitoring modalities in the intraoperative setting due to the fact that it is less invasive than many other monitors, is immediately accessible, and allows for continuous real-time monitoring of cardiac function. However, the minimum training requirements needed for the anesthesia provider to obtain the competency, knowledge, and skills for basic certification in perioperative TEE far exceed those developed for other medical specialties. We believe there is an urgent need to develop (1) practical guidelines for emergent perioperative TEE use for anesthesiologists and (2) a requisite educational curriculum to teach the basic skills necessary to aid in the diagnosis and treatment of cardiac arrest or near-arrest scenarios. The measures elucidated in this report summarize the efforts of the Department of Anesthesiology at the University of Florida in establishing the necessary steps to make this process not only practical, but accessible to all trainees.We hope that these collective efforts will provide more trainees the confidence in utilizing TEE to aid in establishing a diagnosis in critical situations.

Innovative transesophageal echocardiography training and competency assessment for Chinese anesthesiologists: role of transesophageal echocardiography simulation training.

Purpose of review Transesophageal echocardiography (TEE) is playing an invaluable role in diagnosing and monitoring the patients hemodynamics in both cardiac and noncardiac surgery. There have been many obstacles in TEE training. Recent findings The TEE simulation provides an ideal environment for anesthesiologists to practice their echocardiography skills out of the operation room. It consists of a manikin and a dummy probe that enable the trainees to perform a hands-on operation with echocardiographic views and allow a virtual scene consisting of a three-dimensional cardiac model, probe tip and image plane be presented side by side simultaneously. Summary The TEE simulator provides an easy comprehensive learning interface and a friendly environment without the psychological pressure and time limitation frequently experienced in the operation room. The simulator can also be used to assess and evaluate the trainees’ manipulation skills, space thinking, and clinical judgment ability. TEE simulation-based training and testing can be an important part in TEE training curriculum before the trainees start their clinical training in the operation room.

Misplacement of LVAD inflow cannula leads to insufficient output and tissue hypoperfusion

A 63-year-old man with a newly placed left ventricular assist device (LVAD) was emergently taken to the operating room for mediastinal exploration secondary to worsened LVAD output, hemodynamic instability, and organ hypoperfusion. Intraoperative transesophageal echocardiography showed the LVAD inflow cannula intermittently aspirating the atrial septal wall, resulting in occlusion of the inflow cannula. Upon gradual withdrawal of the inflow cannula by several centimeters, dramatic improvements in LVAD output, hemodynamics, and tissue perfusion occurred. Clinical implications of a patient who has a malfunctioning LVAD are discussed.

Blood pressure reduction induced by low dose of epinephrine via different routes in rats.

Background: Epinephrine was recently shown to induce a hypotension episode. Activation of &bgr;2-adrenoceptors with smooth muscle relaxation may be the underlying mechanism. This study investigated the effects of ICI 118551, a &bgr;2-adrenoceptors antagonist, on epinephrine-induced blood pressure reduction via different administration routes in rats. Methods: A total of 144 Sprague Dawley rats were equally randomized into 3 groups (intranasal, intravenous, and intra-arterial administration), each with 4 subgroups: saline + saline, ICI 118551 + saline, saline + epinephrine, and ICI 118551 + epinephrine. All rats were anesthetized while spontaneously breathing. Epinephrine was administered at doses of 5 &mgr;g/kg via nose, 0.25 &mgr;g/kg via femoral vein, and 0.1 &mgr;g/kg via aorta. Mean arterial pressure and heart rate were monitored. Results: Mean arterial pressure decreased in all 3 saline + epinephrine subgroups after administration (P < 0.05), whereas it did not in other subgroups. Heart rate had no significant change in all subgroups. Conclusions: Epinephrine-induced blood pressure reduction can be prevented by ICI 118551 in rats, suggesting that the activation of &bgr;2-adrenoceptors contributes to blood pressure reduction.